This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This study will explore the integrity of oral immune function during SIV infection and how this is impacted by long term ART, where application of potential stimuli (Candida albicans or the TLR 3 ligand polyIC) will be used to measure oral immune integrity during ART. In order to follow the mucosal and systemic immune responses of these animals, we have been optimizing the flow cytometry and functional assays using samples from recycled animals from other studies, in addition to the new animals that have already been purchased for this work. This has involved establishing the multicolor flow assays to document T cell and DC subsets and their activation states in peripheral blood and lymphoid tissues. Functional assays have been established where pieces of mucosal tissues (vs blood cells) are cultured with stimuli (Candida or polyIC) to monitor the cytokine/chemokine responses. Such responses will be measured by luminex/ELISA and PCR for CC/CK mRNA. Most of these assays are in place and the baseline sampling commenced in January. The animals are scheduled to be challenged with SIVmac239 across the tonsils in March and ART will start 2 weeks later. The treatment groups include: untreated uninfected animals, ART-treated uninfected animals, infected untreated animals, and infected ART-treated animals. Blood and mucosal samples will be monitored over time to measure viral and immune parameters. 6-7 months after SIV infection the oral immune function will be assessed by treating the animals with either Candida albicans germ tube or polyIC and measuring local vs systemic immunity and viral loads. Approximately 8 weeks later ART will be stopped. This will help us understand how the oral immune system changes during infection and whether long term ART impacts this biology.